I have two phones, one has a 3.2MP camera, and the other has an 8MP camera. I downloaded the 'Barcode Scanner' app on both phones, it works on the 8MP phone but the 3.2MP phone sometimes doesn't pick up any barcodes at all.

Update: from the discussion in the comment thread, it seems the phone doesn't pick up barcodes because it doesn't have Auto Focus. Is there a way I can get around this?

  • 3
    I suspect it's a focusing/lighting issue. My 1-year phone also has trouble sometimes picking up a barcode in suboptimal conditions. Changing the distance to the barcode and holding your phone still should help. Mar 8, 2012 at 15:07
  • QR codes are designed for phone cameras, so it's no surprise it works with those. You need a pretty good image for standard bar codes to work. Have you tried getting very close to the bar code? Bad lighting can also do it.
    – Ben Brocka
    Mar 8, 2012 at 15:18
  • 3.2 mp camera should be able to pick up bar codes fine... as Martin said, it's probably a lighting or focusing issue.
    – Bryan Denny
    Mar 8, 2012 at 15:19
  • 1
    You could try Google Goggles as well.
    – Peanut
    Apr 16, 2012 at 13:29
  • 1
    Does tap to focus work from the app you're using? Tapping the barcode should focus on it
    – Ben Brocka
    Apr 16, 2012 at 14:17

3 Answers 3


(I'll address your 2nd edit below...)

Some cheap camera modules don't include an auto focus feature, i.e. they are fix-focus'ed to infinity.

Barcode scanners need a near focus though and cannot (or hardly) scan the resulting blurry images that result from infinity-focused fix-focus cameras.

The only way around this would be to attach a macro lens specifically designed for smartphone cameras (also works with fix focus). Search for smartphone macro lens to see some samples.

I already tried that once with an older (also fix-focus) Sony-Ericsson Xperia X8 and it worked back then.


FREE solution:

I've had success with a fraction of a drop of water or oil over the lens of the camera on my ZTE Score. It causes bar codes close to the camera to be in focus, and they read reliably. Enough to form a convex surface, but not so much that it drops off.

The ZTE Score has a smooth back; I dip my finger in oil and, with the lens aimed up, touch the back of the phone where the lens to put a droplet of oil on it. Then I can turn the phone face up (lens down) and I can scan bar codes. If the outer surface of your camera lens isn't flat, this likely won't work, but it's worked with my ZTE score and should work with most low-end (fixed focus) phones.

A clear convex on one side, flat and sticky on the other side piece of plastic would do the trick too; I recall seeing stick-on rubber feet that would have served well, but haven't seen 'em and haven't tried that.

I got tired of doing this every time I wanted to scan a barcode, and just ordered a macro lens.

If the codes don't fit on the screen when in focus, your drop is too big; use less.


As I know, if you put a distance between the phone and the barcode far enough so there's no need for auto-focus, the phone should recognize it. But in some cases, the barcode distance may be far from the specific rectangle by the app, so it will not be recognized. In this case, this situation will differ from one phone to another, and btw I had this case in the past, and it never worked for me.

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